ROTARY MOTION MECHANISM

Abstract: A rotary motion mechanism of this invention comprises a pair of first axis guides (16a, 16b) disposed in parallel to each other in a first direction, a pair of second axis guides (18a, 18b) disposed in parallel to each other in a second direction which is normal to the first direction, a first axis rod (20) disposed in parallel to the first axis guides (16a, 16b) and adapted to move in the second direction in a state in which it remains parallel to the first axis guides (16a, 16b), second axis rod (22) disposed in parallel to the second axis guides (18a, 18b) and adapted to move in the first direction while it remains parallel to the second axis guides (18a, 18b), a moving body (24) adapted to move on the first axis rod (20) and the second axis rod (22) in the first and second directions, respectively, within a rectangular plane surrounded by the first axis guides (16a, 16b) and the second axis guides (18a, 18b), first driving mechanisms (26a, 26b, 26c, 26d) adapted to move the second axis rod (20) in the first direction, second driving mechanisms (34a, 34b, 34c, 34d) adapted to move the first axis rod (20) in the second direction, output shafts (36a, 36b) each rotatable on its axis, lever pieces (38a, 38b) each secured to the moving body (24) at one end and to one end of the output shaft (36a, 36b) at the other end so as to rotate the output shafts (36a, 36b) when the moving body (24) rotates around the output shafts (36a, 36b).

Description: The present invention relates to a rotary motion drive system, more precisely relates to a rotary motion drive system, which is capable of converting linear motion into rotary motion. There have been known a reciprocating internal combustion engine, an oil motor, etc. as the rotary motion drive system, which is capable of converting linear motion into rotary motion. In each conventional rotary motion drive system, linear motion of a piston, which is reciprocatively moved in a cylinder, is converted into rotary motion of a crank shaft. The conventional reciprocating engine and the oil motor, however, have following disadvantage. The piston and the crank shafts are connected with a connecting rod. One end of the piston and one end of the connecting rod are pivotably connected each other, so that they can be mutually inclined. And one end of the crank shaft and the other end of the connecting rod are also pivotably connected each other, so that they can be mutually inclined. Even if the thrust force of the piston is transmitted to the connecting rod, the thrust force cannot be perfectly transmitted to the crank shaft when the connecting rod is inclined with respect to the piston and the crank shaft. Namely, the thrust force of the piston is divided between the piston and the connecting rod, and the component force transmitted to the connecting rod is further divided between the connecting rod and the crank shaft, so that a great loss cannot be avoided. Thus, the rotary torque of the crank shaft must be smaller with respect to the thrust force of the piston, so that the efficiency of converting the linear motion into the rotary motion must be lower. US-A-4995 277 discloses in accordance with the features of the preamble of claim 1 a two dimensional drive system for moving a slider selectively in two perpendicular directions to locate the slider accurately at any position within an associated plane. More particularly, the slider travels on first and second rods perpendicular to one another, both ends of each rod being connected to an associated pair of travellers themselves movable along associated parallel guides, the guides for each rod being perpendicular to one another whereby the desired selective movement of the slider can be achieved. It would be desirable to be able to provide a rotary motion drive system capable of converting linear motion into rotary motion more efficiently than heretofore. According to the present invention, there is provided a rotary motion drive system comprising by a pair of parallel first guides extending in a first direction; a pair of parallel second guides extending in a second direction perpendicular to the first direction; a first rod arranged parallel with said first guides, said first rod being maintained parallel with said first guides and being movable in the second direction; a second rod arranged parallel with said second guides, said second rod being maintained parallel with said second guides and being movable in the first direction; a moving body movable on said first rod and on said second rod in the first direction and the second direction respectively within a rectangular plane bounded by said first guides and said second guides; a first driving mechanism for moving said second rod in the first direction, and a second driving mechanism for moving said first rod in the second direction, characterised by an output shaft extending along, to be rotatable about, an axis extending perpendicular to said rectangular plane bounded by the first and second guides, and a lever one end of which is pivotally connected to the moving body and the other end of which is fixed to the output shaft, the arrangement being such that movement of the moving body along the first and second rods results in movement of the body in a circle about said axis whilst maintaining a fixed orientation of the body within said plane, and consequential rotation of the output shaft about said axis by the lever. It will be appreciated that all the force transmitting loss that results from conversion of the linear thrust force of the first and second rods into rotary motion occurs at the point of connection of the moving body and the lever, whereby a more efficient systems than heretofore is provided. Preferably the drive system further comprises a first mechanism for keeping said first rod parallel to said first guides, and a second mechanism for keeping said second rod parallel to said second guides, such an arrangement ensuring that the first and second rods are maintained perpendicular with one another, a stable rotary torque is gained from the output shaft, and vibration and generating noise are prevented. This is particularly advantageous with longer levers which provide greater torque. By way of examples only, embodiments of the invention will now be described in greater detail with reference to the accompanying drawings of which: Fig. 1 is a plan view of a first embodiment of the rotary motion drive system of the present invention; Fig. 2 is a plan sectional view of the system shown in Fig. 1; Fig. 3 is a front sectional view of the system shown in Fig. 1; Fig. 4 is a plan sectional view of a second embodiment of the rotary motion drive system; Fig. 5 is a front sectional view of the system shown in Fig. 4; Fig. 6 is a plan view of a third embodiment of the rotary motion drive system; and Fig. 7 is a front view of the system shown in Fig. 6. The first embodiment will be explained with reference to Figs. 1-3. Fig. 1 is a plan view of the embodiment (note the bottom view thereof is same); Fig. 2 is a plan sectional view showing inner structure thereof; and Fig. 3 is a front sectional view thereof. A symbol 10 is an upper cover, which is a part of a system proper; a symbol 12 is a lower cover, which is also a part of the system proper. The upper cover 10 and the lower cover 12 are connected by connecting blocks 14, which are provided at four corners. Symbols 16a and 16b are a pair of X-guides (first guides) arranged parallel in an X-direction (first direction). The X-guides 16a and 16b are capable of moving in the X-direction, their details will be described later. Symbols 18a and 18b are a pair of Y-guides (second guides) arranged parallel in a Y-direction (second direction). The Y-guides 18a and 18b are arranged perpendicular to the X-guides 16a and 16b. The Y-guides 18a and 18b are capable of moving in the Y-direction, their details will be described later. A symbol 20 is an X-rod (first rod) arranged parallel to the X-guides 16a and 16b, and its ends are respectively fixed to the Y-guides 18a and 18b. Thus, the X-rod 20 is capable of moving in the Y-direction with the movement of the Y-guides 18a and 18b in the Y-direction and keeping parallel to the X-guides 16a and 16b. A symbol 22 is a Y-rod (second rod) arranged parallel to the Y-guides 18a and 18b, and its ends are respectively fixed to the X-guides 16a and 16b. Thus, the Y-rod 22 is capable of moving in the X-direction with the movement of the X-guides 16a and 16b in the X-direction and keeping parallel to the Y-guides 18a and 18b. A symbol 24 is a moving body, the X-rod 20 is pierced through the lower part thereof; the Y-rod 22 is pierced through the upper part thereof. The moving body 24 is capable of slidinng on the X-rod 20 and the Y-rod 22 with slide bearings in the X- and the Y-directions. With the movement of the X-rod 20 and the Y-rod 22 in X- and the Y-directions, the moving body 24 can be executed two dimensional movement in a square plane 28, which are bounded by the X-guides 16a and 16b and the Y-guides 18a and 18b. Symbols 26a, 26b, 26c and 26d are X-cylinder units, whcih are one of examples of first driving mechanisms, and they are fixed to the connecting blocks 14 and arranged in the X-direction. When compressed air is charged via air-ports 30a, 30b, 30c and 30d of the X-cylinder units 26a, 26b, 26c and 26d, pistons 32a, 32b, 32c and 32d are driven. Each end of the X-guide 16a is respectively fixed to the pistons 32a and 32b, so that the X-guide 16a is moved in the X-direction by selectively charging compressed air to the X-cylinder units 26a and 26b. On the other hand, each end of the X-guide 16b is respectively fixed to the pistons 32c and 32d, so that the X-guide 16b is moved in the X-direction by selectively charging compressed air to the X-cylinder units 26c and 26d. Symbols 34a, 34b, 34c and 34d are Y-cylinder units, whcih are one of examples of second driving mechanisms, and they are fixed to the connecting blocks 14 and arranged in the Y-direction. When compressed air is charged via air-ports 30e, 30f, 30g and 30h of the Y-cylinder units 34a, 34b, 34c and 34d, pistons 32e, 32f, ..... (pistons of the Y-cylinder units 34c and 34d are not shown) are driven. Each end of the Y-guide 18a is respectively fixed to the pistons 32e and the piston of the Y-cylinder unit 34d, so that the Y-guide 18a is moved in the Y-direction by selectively charging compressed air to the Y-cylinder units 34a and 34d. On the other hand, each end of the Y-guide 18b is respectively fixed to the pistons 32f and the piston of the Y-cylinder unit 34c, so that the Y-guide 18b is moved in the Y-direction by selectively charging compressed air to the Y-cylinder units 34b and 34c. Symbols 36a and 36b are output shafts, and they are respectively rotatably attached to the upper cover 10 and the lower cover 12 with ball bearings and capable of rotating about their own axes. End sections of the output shafts 36a and 36b are projected from the upper cover 10 and the lower cover 12, so that they can be connected with driven members (not shown). Symbols 38a and 38b are levers, and they rotate the output shafts 36a and 36b when the moving body 24 moves round the output shafts 36a and 36b. One end of the lever 36a is pivotably connected to an upper face of the moving body with a ball bearing; the other end is fixed to a lower end of the output shaft 36a. On the other hand, one end of the lever 36b is pivotably connected to a lower face of the moving body with a ball bearing; the other end is fixed to an upper end of the output shaft 36b. Successively, the action of the rotary motion drive system will be explained. In the present embodiment, the X-cylinder units 26a and 26d are simultaneously driven; the X-cylinder units 26b and 26c are simultaneously driven; the Y-cylinder units 34a and 34b are simultaneously driven; and the Y-cylinder units 34c and 34d are simultaneously driven. The cylinder units are controlled by a computer control unit, which controls a switching valve (not shown) for selectively charging compressed air supplied from a compressor, not shown. In Fig. 2, for example, when compressed air is charged to the X-cylinder units 26b and 26c and the Y-cylinder units 34a and 34b, X-guides 16a and 16b and the Y-rod 22 are biased rightward in the X-direction; the Y-guides 18a and 18b and the X-rod 20 are biased downward in the Y-direction. But the output shafts 36a and 36b are able to rotate but unable to move their positions, so that the moving body 24, which is connected with the output shafts 36a and 36b by the levers 38a and 38b, is moved in the clockwise direction from the present position to a position A. At the position A, when compressed air is continuously charged to the Y-cylinder units 34a and 34b; charging compressed air to the X-cylinder units 26b and 26c is stopped; and compressed air is charged to the X-cylinder units 26a and 26d, the Y-guides 18a and 18b and the X-rod 20 are biased downward in the Y-direction; the X-guides 16a and 16b and the Y-rod 22 are biased leftward in the X-direction. Thus, the moving body 24 is moved in the clockwise direction from the position A to a position B. At the position B, when compressed air is continuously charged to the X-cylinder units 26a and 26d; charging compressed air to the Y-cylinder units 34a and 34b is stopped; and compressed air is charged to the Y-cylinder units 34c and 34d, the X-guides 16a and 16b and the Y-rod 22 are biased leftward in the X-direction; the Y-guides 18a and 18b and the X-rod 20 are biased upward in the Y-direction. Thus, the moving body 24 is moved in the clockwise direction from the position B to a position C. At the position C, when compressed air is continuously charged to the Y-cylinder units 34c and 34d; charging compressed air to the X-cylinder units 26a and 26d is stopped; and compressed air is charged to the X-cylinder units 26b and 26c, the Y-guides 18a and 18b and the X-rod 20 are biased upward in the Y-direction; the X-guides 16a and 18b and the Y-rod 22 are biased rightward in the X-direction. Thus, the moving body 24 is moved in the clockwise direction from the position C to a position D. By repeating above described actions, the moving body 24 can be continuously moved along an orbit 40, so that the output shafts 36a and 36b are continuously rotated in the clockwise direction. With this rotation, the driven member or members, which are connected with the output shafts 36a and/or 36b, can be rotated. Note that, in case of rotating the output shafts 36a and 36b in the counterclockwise direction, the X-cylinder units 26a, 26b, 26c and 26d and the Y-cylinder units 34a, 34b, 34c and 34d are driven in the reverse order. During the operation, the inertia is generated by the orbital movement of the moving body 24 round the output shafts 36a and 36b, and a short time is necessary for the X-cylinder units 26a, 26b, 26c and 26d and the Y-cylinder units 34a, 34b, 34c and 34d to charge and discharge compressed air, so that actual switching positions, at which compressed air is charge to or discharge from the X-cylinder units 26a, 26b, 26c and 26d and the Y-cylinder units 34a, 34b,34c and 34d, must be set slightly before the positions A, B, C and D. To detect the switching positions, a timing plate 42, for example, is fixed to the output shaft 36b, which actuates a micro switch 44 so as to send detecting signals to the computer control unit when the timing plate rotates predetermined angle. Besides the timing plate 42 and the micro switch 44, any means for detecting the switching positions, e.g., a rotary encoder, can be employed as the detecting means. In the rotary motion drive system of the present embodiment, the rotation of the output shafts 36a and 36b is stopped by stopping charging compressed air to the X-cylinder units and the Y-cylinder units. By stopping the air charge, the movement of the X-guides 16a and 16b or the Y-guides 18a and 18b is stopped, so that the orbital movement of the moving body 24 and the rotation of the output shafts 36a and 36b are stopped. In the present embodiment, a pair of X-guides 16a and 16b (or a pair of Y-guides 18a and 18b) are simultaneously driven by two X-cylinder units 26a and 26d or two X-cylinder units 26b and 26c (or two Y-cylinder units 34a and 34b or two Y-cylinder units 34c and 34d), so that the X-guides 16a and 16b (or the Y-guides 18a and 18b) can be simultaneously moved in the same direction and in the same length. Therefore, vibration of the system and generating noise can be prevented, further stable high speed operation can be executed. As described above, when the moving body 24 moves from the position shown in Fig. 2 toward the position B via the position A, for example, the states of the X-cylinder units and the Y-cylinder units are changed between the air-charging status and the air-discharging status shortly before reaching the position A. When the moving body is close to the position A, the moving length in the X-direction is quite short, so the inertia smoothly affects the moving body 24 without shock even if said status is changed between the air-charging status and the air-discharging status. Therefore, the moving body 24 can be moved round stably. Especially it is advantageous when the moving body 24 is moved round at high speed. In the present embodiment, the linear motion of the X-guides 16a and 16b and the Y-guides 18a and 18b in the X-and the Y-directions are converted into the orbital movement of the moving body 24, then the orbital movement is further converted into the rotation of the output shafts 36a and 36b by the levers 38a and 38b, so that the force-transmitting-loss is occurred only at the connecting point of the moving body 24 and the levers 38a and 38b, and the efficiency of converting the linear motion or the linear thrust force of the X-guides 16a and 16b and the Y-guides 18a and 18b into the rotary motion or the rotary torque of the output shafts 36a and 36b can be higher. The rotary motion drive system of the present embodiment has a simple mechanical structure, so the change of the size of the system, which has been very difficult for the conventional rotary motion drive systems, e.g., a reciprocating engine, an oil motor, can be easily executed. Especially the rotary torque of the output shafts 36a and 36b can be controlled by merely adjusting the length of the levers 38a and 38b, so that various rotary torque can be gained from one system. The second embodiment will be explained with reference to Figs. 4 and 5. Note that, elements which have been described in the first embodiment are assigned same symbols and explanation will be omitted. In the first embodiment, if the X-rod 20 and the Y-rod 22 are long, by the movement of the moving body 24, the position in the Y-direction of the one end of the X-rod 20 is apt to shift with respect to that of the other end thereof; the position in the X-direction of the one end of the Y-rod 22 is apt to shift with respect to that of the other end thereof. Then, the rotary motion drive system of the second embodiment has a first parallel mechanism for keeping the X-rod parallel to the X-guides and a second parallel mechanism for keeping the Y-rod parallel to the Y-guides. Firstly, the constitution of the system will be explained. Symbols 50a and 50b are a pair of X-guides (the first guides), which are arranged parallel in the X-direction (the first direction). The X-guides 50a and 50b are linear guides, which are fixed on an upper face of the lower cover 12. X-moving blocks 52a and 52b are capable of respectively sliding on the X-guides 50a and 50b. Symbols 54a and 54b are a pair of Y-guides (the second guides), which are arranged parallel in the Y-direction (the second direction). The Y-guides 54a and 54b are arranged perpendicular to the X-guides 50a and 50b. The Y-guides 54a and 54b are also linear guides, which are fixed on the upper face of the lower cover 12. Y-moving blocks 56a and 56b are capable of respectively sliding on the Y-guides 54a and 54b. Each end of an X-rod 58 (the first rod) is rotatably connected to each of Y-moving blocks 56a and 56b with a bearing. There are grooved three spline grooves 60a, which are formed in the longitudinal direction, on an outer circumferential face of the X-rod 58. Each end of a Y-rod 62 (the second rod) is rotatably connected to each of X-moving blocks 52a and 52b with a bearing. There are grooved three spline grooves 60b, which are formed in the longitudinal direction, on an outer circumferential face of the Y-rod 62. There is provided an X-rotor 64, which is capable of rotating about its own axis, in a lower part of the moving body 24. The X-rod 58 is pierced through the X-rotor 64; the X-rotor 64 is engaged with the spline grooves 60a. With this structure, the X-rotor 64 is capable of moving on the X-rod 58 in the X-direction and rotating about own axis together with the X-rod 58. On the other hand, there is provided a Y-rotor 66, which is capable of rotating about its own axis, in an upper part of the moving body 24. The Y-rod 62 is pierced through the Y-rotor 66; the Y-rotor 66 is engaged with the spline grooves 60b. With this structure, the Y-rotor 66 is capable of moving on the Y-rod 62 in the Y-direction and rotating about own axis together with the Y-rod 62. Symbols 68a and 68b are X-rodless cylinder units, which are one of examples of the first driving mechanism, and they are spanned in the X-direction between the connecting blocks 14. By charging compressed air to air-ports 70a, 70b, 70c and 70d of the X-rodless cylinder units 68a and 68b, sliders 72a and 72b are moved on the X-rodless cylinder units 68a and 68b in the X-direction. The slider 72a is connected to the X-moving block 52a; the slider 72b is connected to the X-moving block 52b. Thus, the Y-rod 62 and the moving body 24 are moved in the X-direction by selectively charging compressed air to the X-rodless cylinder units 68a and 68b. Symbols 74a and 74b are Y-rodless cylinder units, which are one of examples of the second driving mechanism, and they are spanned in the Y-direction between the connecting blocks 14. By charging compressed air to air-ports 70e, 70f, 70g and 70h of the Y-rodless cylinder units 74a and 74b, sliders 72c and 72d are moved on the Y-rodless cylinder units 74a and 74b in the Y-direction. The slider 72c is connected to the Y-moving block 56a; the slider 72d is connected to the Y-moving block 56b. Thus, the X-rod 58 and the moving body 24 are moved in the Y-direction by selectively charging compressed air to the Y-rodless cylinder units 74a and 74b. Symbols 76a and 76b are X-racks, which are fixed on the upper face of the lower cover 12 and arranged parallel in the X-direction. Symbols 78a and 78b are Y-racks, which are fixed on the upper face of the lower cover 12 and arranged parallel in the Y-direction. Symbols 80a and 80b are Y-pinions, each of which is fixed at each end of the X-rod 58. The Y-pinions 80a and 80b are respectively engaged with the Y-racks 78a and 78b. When the X-rod 58 is moved in the Y-direction, the Y-pinions 80a and 80b roll on the Y-racks 78a and 78b. During the rotation, the X-rod 58 is rotated together with the Y-pinions 80a and 80b. While the X-rod 58 is moved, even if external force works the X-rod 58 to incline with respect to the X-axis, the X-rod 58 is kept parallel to the X-guides 50a and 50b because the Y-pinions 80a and 80b engage with the Y-racks 78a and 78b. Namely, the Y-racks 78a and 78b and the Y-pinions 80a and 80b role as the first parallel mechanism. Symbols 82a and 82b are X-pinions, each of which is fixed at each end of the Y-rod 62. The X-pinions 82a and 82b are respectively engaged with the X-racks 76a and 76b. When the Y-rod 62 is moved in the X-direction, the X-pinions 82a and 82b roll on the X-racks 76a and 76b. During the rotation, the Y-rod 62 is rotated together with the X-pinions 82a and 82b. While the Y-rod 62 is moved, even if external force works the Y-rod 62 to incline with respect to the Y-axis, the Y-rod 62 is kept parallel to the Y-guides 54a and 54b because the X-pinions 82a and 82b engage with the X-racks 76a and 76b. Namely, the X-racks 76a and 76b and the X-pinions 82a and 82b role as the second parallel mechanism. In the rotary motion drive system of the second embodiment, the Y-rod 62 and the moving body 24 can be moved in the X-direction by simultaneously charging compressed air to the air-ports 70a and 70d, or the air-ports 70b and 70c of the X-rodless cylinder units 68a and 68b. On the other hand, the X-rod 58 and the moving body 24 can be moved in the Y-direction by simultaneously charging compressed air to the air-ports 70e and 70f, or the air-ports 70h and 70g of the Y-rodless cylinder units 74a and 74b. In the present embodiment too, the X-rodless cylinder units 68a and 68b and the Y-rodless cylinder units 74a and 74b are controlled by the computer control unit, which controls the switching valve (not shown) for selectively charging compressed air supplied from the compressor. In the second embodiment, any means for detecting the switching positions of the X-rodless cylinder units 68a and 68b and the Y-rodless cylinder units 74a and 74b (the timing plate and the micro switch, the rotary encoder, etc.) may be employed as the detecting means as well as the first embodiment. In the second embodiment too, the output shafts 36a and 36b are rotated about their own axes by moving the moving body 24 round the output shafts 36a and 36b. Since the system of the second embodiment has the first and the second parallel mechanisms, the inclination of the X-rod 58 and the Y-rod 62 with respect to the X-guides 50a and 50b and the Y-guides 54a and 54b can be prevented even if working points of the external force, which causes said inclination, on the X-rod 58 and the Y-rod 62 is changed with the movement of the moving body 24, so that vibration of the system and generating noise can be prevented and stable rotary torque can be gained from the output shafts 36a and 36b. Especially the system will be more advantageous in case of having long levers 38a and 38b so as to get greater rotary torque. The third embodiment will be explained with reference to Figs. 6 and 7. The rotary motion drive system of the third embodiment is a combination of a plurality of sub-rotary motion drive systems, each of which is the rotary motion drive systems of the first embodiment. The system shown has a couple of sub-rotary motion drive systems 90a and 90b, which are vertically connected each other. The sub-systems 90a and 90b are mutually shifted with angle of 45 ° in a plane. A moving body 92a of the sub-system 90a and a moving body 92b of the sub-system 90b are mutually connected, so that the both are capable of moving together. In the third embodiment, the rotary motion drive system has 16 air cylinder units 94, and two of them are simultaneously driven so as to move the moving bodies 92a and 92b round the output shafts 36a and 36b, so that the rotary motion (the rotary torque) can be gained from the output shafts 36a and 36b. By combining a plurality of the sub-systems 90a and 90b as disclosed in the third embodiment, a multiple switching points of the air cylinder units 94 can be set, so that stable torque can be gained and the moving bodies 92a and 92b can be stably moved round. With the stable operation, vibration of the system can be reduced, so the system is advantageous for high speed operation. Further, by combining a plurality of the sub-systems 90a and 90b, the total output torque can be greater. In case of combining a plurality of the sub-systems 90a and 90b, the moving bodies 92a and 92b may be connected integrally, and the output shafts may be mutually connected by a coupler, etc.. Preferred embodiments of the present invention have been described in detail but the present invention is not limited to above described embodiments, the first driving mechanism and the second driving mechanism, for example, are not limited to the air cylinder units or the rodless cylinder units, other linear motion means, e.g., a hydraulilc cylinder unit, a linear motor, a solenoid unit, an internal-combustion engine with a linear motion piston, can be employed, namely many modifications can be allowed without deviating from the scope of the invention.

Claims: A rotary motion drive system comprising a pair of parallel first guides (16a, 16b ; 50a, 50b) extending in a first direction (X); a pair of parallel second guides (18a, 18b ; 54a, 54b) extending in a second direction (Y) perpendicular to the first direction (X); a first rod (20 ; 58) arranged parallel with said first guides, said first rod being maintained parallel with said first guides and being movable in the second direction (Y); a second rod (22 ; 62) arranged parallel with said second guides, said second rod being maintained parallel with said second guides and being movable in the first direction (X); a moving body (24) movable on said first rod and on said second rod in the first direction (X) and the second direction (Y) respectively within a rectangular plane bounded by said first guides and said second guides ; a first driving mechanism (26a to 26d) moving said second rod in the first direction (X), and a second driving mechanism (34a to 34d) moving said first rod in the second direction (Y), characterised by an output shaft (36a) extending along, to be rotatable about, an axis extending perpendicular to said rectangular plane bounded by the first and second guides (16a, 16b, 18a, 18b ; 50a, 50b, 54a, 54b), and a lever (38a) one end of which is pivotally connected to the moving body (24) and the other end of which is fixed to the output shaft, the arrangement being such that movement of the moving body along the first and second rods (20,22 ; 58, 62) results in movement of the body in a circle about said axis whilst maintaining a fixed orientation of the body within said plane, and consequential rotation of the output shaft about said axis by the lever. A rotary motion drive system according to claim 1 and further comprising a first mechanism for keeping said first rod (58) parallel to said first guides (50a, 50b), and a second mechanism for keeping said second rod (62) parallel to said second guides (54a, 54b). A rotary motion drive system according to claim 2 wherein said first mechanism and said second mechanism are each rack and pinion mechanisms (76a, 76b, 82a, 82b). A rotary motion drive system according to any one of claims 1 to 3 wherein said first driving mechanism and said second driving mechanism each comprise air cylinder units (26a to 26d, 34a to 34d). A rotary motion drive system according to any one of claims 1 to 3 wherein said first driving mechanism and said second driving mechanism each comprises a ball screw and a motor for rotating said ball screw. A rotary motion drive system as claimed in any one of claims 1 to 5 wherein a plurality of sets of said outputs shafts (36a, 36b) and said levers (38a, 38b) are provided. A rotary motion drive system according to claim 4 and claims dependent therefrom and further comprising means (42, 44) for detecting switching positions of said air cylinder units (26a to 26d, 34a to 34d) at which an air-charging status and an air-discharging status of said air cylinder units are changed.

Inventors: YANAGISAWA KEN, YANAGISAWA, KEN
Applicants: YUGEN KAISHA SOZOAN
Application year: 1994
Main classification: F16H25
IPC codes: F16H35, F16H21, F16H37